diff --git a/gnss/1.0/default/GnssXtra.cpp b/gnss/1.0/default/GnssXtra.cpp
new file mode 100644
index 0000000..065bb33
--- /dev/null
+++ b/gnss/1.0/default/GnssXtra.cpp
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "GnssHAL_GnssXtraInterface"
+
+#include "GnssXtra.h"
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace V1_0 {
+namespace implementation {
+
+std::vector<std::unique_ptr<ThreadFuncArgs>> GnssXtra::sThreadFuncArgsList;
+sp<IGnssXtraCallback> GnssXtra::sGnssXtraCbIface = nullptr;
+bool GnssXtra::sInterfaceExists = false;
+
+GpsXtraCallbacks GnssXtra::sGnssXtraCb = {
+    .download_request_cb = gnssXtraDownloadRequestCb,
+    .create_thread_cb = createThreadCb,
+};
+
+GnssXtra::~GnssXtra() {
+    sThreadFuncArgsList.clear();
+}
+
+pthread_t GnssXtra::createThreadCb(const char* name, void (*start)(void*), void* arg) {
+    return createPthread(name, start, arg, &sThreadFuncArgsList);
+}
+
+GnssXtra::GnssXtra(const GpsXtraInterface* xtraIface) : mGnssXtraIface(xtraIface) {
+    /* Error out if an instance of the interface already exists. */
+    LOG_ALWAYS_FATAL_IF(sInterfaceExists);
+    sInterfaceExists = true;
+}
+
+void GnssXtra::gnssXtraDownloadRequestCb() {
+    if (sGnssXtraCbIface == nullptr) {
+        ALOGE("%s: GNSS Callback Interface configured incorrectly", __func__);
+        return;
+    }
+
+    sGnssXtraCbIface->downloadRequestCb();
+}
+
+// Methods from ::android::hardware::gnss::V1_0::IGnssXtra follow.
+Return<bool> GnssXtra::setCallback(const sp<IGnssXtraCallback>& callback)  {
+    if (mGnssXtraIface == nullptr) {
+        ALOGE("%s: Gnss Xtra interface is unavailable", __func__);
+        return false;
+    }
+
+    sGnssXtraCbIface = callback;
+
+    return (mGnssXtraIface->init(&sGnssXtraCb) == 0);
+}
+
+Return<bool> GnssXtra::injectXtraData(const hidl_string& xtraData)  {
+    if (mGnssXtraIface == nullptr) {
+        ALOGE("%s: Gnss Xtra interface is unavailable", __func__);
+        return false;
+    }
+
+    char* buf = new char[xtraData.size()];
+    const char* data = xtraData.c_str();
+
+    memcpy(buf, data, xtraData.size());
+
+    int ret = mGnssXtraIface->inject_xtra_data(buf, xtraData.size());
+    delete[] buf;
+    return (ret == 0);
+}
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android